21808733499 has 12 divisors (see below), whose sum is σ = 36001718896. Its totient is φ = 12462133392.

The previous prime is 21808733491. The next prime is 21808733503. The reversal of 21808733499 is 99433780812.

21808733499 is a `hidden beast` number, since 2 + 1 + 80 + 8 + 73 + 3 + 499 = 666.

It is not a de Polignac number, because 21808733499 - 2³ = 21808733491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21808733491) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 173085124 + ... + 173085249.

Almost surely, 2^21808733499 is an apocalyptic number.

21808733499 is a deficient number, since it is larger than the sum of its proper divisors (14192985397).

21808733499 is a wasteful number, since it uses less digits than its factorization.

21808733499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346170386 (or 346170383 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 21808733499 in words is "twenty-one billion, eight hundred eight million, seven hundred thirty-three thousand, four hundred ninety-nine".